Method of measuring biological information using light and apparatus of measuring biological information using light

ABSTRACT

A compact apparatus of measuring biological information using light capable of measuring biological information with high reproducibility and accuracy is provided. The apparatus of measuring biological information using light comprises a light source part irradiating an organism, a light receiving part receiving light propagating from the light source part through the inside of the organism and outgoing from the surface of the organism, a forming part forming the surface of the organism into a predetermined shape by applying a pressure thereto, and a calculation part calculating information of the relation between the amount of received light and the biological information of the organism previously determined based on the amount of light received in the light receiving part.

This application is a U.S. national phase application of PCTInternational Application PCT/JP03/00586.

TECHNICAL FIELD

The present invention relates to a method and apparatus of measuringbiological information using light capable of optically measuringbiological information including the thickness of subcutaneous fat, thepercent of body fat, the concentration of glucose in an organism andconcentration of oxygen in an organism.

BACKGROUND ART

A method has been known in which light enters an organism from a lightsource placed on the surface of the organism. The light appears again onthe surface of the organism after propagating through the inside of theorganism while being scattered and absorbed. The light received on thesurface is used to measure the concentration of an absorbing material inthe organism or the thickness of a tissue. FIG. 38 shows a positionalrelation between a light source and a light receiving element and anorganism in a subcutaneous fat thickness measuring apparatus describedin Japanese Patent Laid-Open No. 2000-155091 as one example of themethod. The disclosure of Japanese Patent Laid-Open No. 2000-155091 isincorporated herein by reference in its entirety. A light source 302 anda measuring light receiving element 303 are placed on the surface of anorganism 301. Given that the organism has a structure of a parallel flatplate having three layers of a skin 305, a subcutaneous fat 306 and amuscle 307 as shown in FIG. 38, light 308 received by the measuringlight receiving element 303 has a correlation with the thickness of thesubcutaneous fat 306 due to a difference in absorption and scatteringcharacteristics between organic tissues. However, the amount of light308 received by the measuring light receiving element 303 varies undersignificant influences of changes in blood flows of the skin 305 and thesubcutis. Therefore, a correcting light receiving element 304 is placednear the light source 302 (1 to 6 mm from the light source 302), andlight 308 received by the measuring light receiving element 303 iscorrected by the amount of light 309 received by the correcting lightreceiving element 304, thereby making it possible to measure thethickness of subcutaneous fat with high accuracy.

However, because the organic tissue is not strictly a parallel flatplate as shown in FIG. 39, and arms and legs have cylindrical shapes asshown in FIG. 40, the measurement accuracy is compromised by a localchange in thickness.

Also, because the organic tissue is soft and hence highly deformable,the shape of the surface of the organism 301 varies for each measurementeven in the same person and the same site, and therefore the amount ofreceived light is varied to compromise reproducibility.

Also, in the case where the subcutaneous fat 306 is thick, the distancebetween the light source 302 and the measuring light receiving element303 should be increased for receiving light propagated through a deeperpart in the organism by the measuring light receiving element 303.Therefore, there is a disadvantage that the measuring apparatus isscaled up.

Also, in the case where the subcutaneous fat 306 is thick, the distancebetween the light source 302 and the measuring light receiving element303 is increased, and therefore the amount of light received in themeasuring light receiving element 303 is reduced to compromise themeasurement accuracy.

Also, in the case where the subcutaneous fat 306 is thick, the lightreception sensitivity in the measuring light receiving element 303should be improved, and therefore the accuracy and sensitivity of themeasuring light receiving element 303 should be enhanced, thus raising adisadvantage that expensive parts are required.

Also, in the case where the subcutaneous fat 306 is thick, lightincident from sources other than the light source 302 such as sunlightinto the organism is measured even if the sensitivity of the measuringlight receiving element 303 is improved, and therefore the surface ofthe organism 301 should be shielded sufficiently.

Also, in the conventional subcutaneous fat thickness measuringapparatus, the thickness of the subcutaneous fat 306 is changed inassociation with the variation in contact pressure applied to theorganism by the light source 302 and the measuring light receivingelement 303 on the surface of the organism, and therefore the thicknessof the subcutaneous fat 306 varies for each measurement to compromisemeasurement reproducibility. This problem is significant particularlywhen the subcutaneous fat is thick.

In addition, the subcutaneous fat 306 is deformed due to the contactpressure, and therefore the amount of blood in the subcutaneous fat 306is changed to cause a variation in absorption characteristics by theblood in the subcutaneous fat 306. Consequently, the amount of lightreceived in the measuring light receiving element 303 fluctuates tocompromise measurement reproducibility.

DISCLOSURE OF THE INVENTION

In consideration of the problems described above, the present inventionprovides, as its object, a compact method of measuring biologicalinformation using light and apparatus of measuring biologicalinformation using light capable of measuring biological information suchas the thickness of subcutaneous fat and the percent of body fat withhigh reproducibility and accuracy.

Also, in consideration of the problems described above, the presentinvention provides, as its object, a method of measuring biologicalinformation using light and an apparatus of measuring biologicalinformation using light capable of measuring the thickness ofsubcutaneous fat with high reproducibility and accuracy.

To solve the above problems, a first aspect of the present invention isa method of measuring biological information comprising:

-   -   a first step of forming the surface of an organism into a        predetermined shape by applying a pressure thereto;    -   a second step of irradiating said organism with light;    -   a third step of receiving said light propagating through the        inside of said organism and outgoing from the surface of said        organism; and    -   a fourth step of calculating biological information of said        organism using information of the relation between the amount of        said received light and the biological information of said        organism previously determined based on the amount of said light        received in said third step.

A second aspect of the present invention is the method of measuringbiological information according to the first aspect of the presentinvention, wherein in said fourth step, the biological information ofsaid organism is calculated using information of the relation betweenthe amount of said received light and the biological information of saidorganism after said pressure reaches a level equal to or greater thanpredefined value, previously determined based on the amount of saidreceived light after said pressure reaches a level equal to or greaterthan a predefined value.

A third aspect of the present invention is the method of measuringbiological information according to the first aspect of the presentinvention, comprising a fifth step of measuring said pressure,

-   -   wherein in said fourth step, the biological information of said        organism is calculated using information of the relation between        the amount of said received light and said pressure and the        biological information of said organism previously determined        based on the amount of said light received in said third step        and said pressure measured in said fifth step.

A fourth aspect of the present invention is the method of measuringbiological information according to the second aspect of the presentinvention, wherein the predefined value of said pressure is about 7 kPaor greater.

A fifth aspect of the present invention is the method of measuringbiological information according to the first aspect of the presentinvention, wherein the central wavelength of said light applied in saidsecond step is a wavelength of about 500 nm to 1000 nm.

A sixth aspect of the present invention is the method of measuringbiological information according to the first aspect of the presentinvention, wherein in said fourth step, the biological information ofsaid organism is calculated at a time when a predetermined amount oftime passes after said pressure reaches a predetermined pressure.

A seventh aspect of the present invention is the method of measuringbiological information according to the sixth aspect of the presentinvention, comprising a sixth step of detecting that said pressurereaches said predefined value,

-   -   wherein in said fourth step, the biological information of said        organism is calculated based on the amount of said light        received in said third step at a time when a predetermined        amount of time passes after it is detected that said pressure        reaches said predefined value in said sixth step.

An eighth aspect of the present invention is the method of measuringbiological information according to the seventh aspect of the presentinvention, wherein said predetermined amount of time is about 200 ms orgreater.

A ninth aspect of the present invention is the method of measuringbiological information according to the first aspect of the presentinvention, wherein in said fourth step, the biological information ofsaid organism is calculated after the amount of said received light isstabilized.

A tenth aspect of the present invention is the method of measuringbiological information according to the ninth aspect of the presentinvention, comprising a sixth step of detecting that said pressurereaches said predefined value,

-   -   wherein in said fourth step, variations in the amount of said        light received in said third step are monitored when it is        detected that said pressure reaches said predefined value in        said sixth step, and the biological information of said organism        is calculated based on the amount of said received light        acquired when the variations in said amount of received light        are within a predetermined value.

An eleventh aspect of the present invention is the method of measuringbiological information according to the tenth aspect of the presentinvention, wherein the variations in said amount of received light beingwithin a predetermined value means the variations in said amount ofreceived light being within about ±10%.

A twelfth aspect of the present invention is an apparatus of measuringbiological information using light comprising:

-   -   a light source part irradiating an organism;    -   a light receiving part receiving light propagating from said        light source part through the inside of said organism and        outgoing from the surface of said organism;    -   a forming part forming the surface of said organism into a        predetermined shape by applying a pressure thereto; and    -   a calculation part calculating biological information of said        organism using information of the relation between the amount of        said received light and the biological information of said        organism previously determined based on the amount of said light        received in said light receiving part.

A thirteenth aspect of the present invention is the apparatus ofmeasuring biological information using light according to the twelfthaspect of the present invention, comprising a pressure detecting partdetecting that the pressure applied to the surface of said organism bysaid forming part reaches a level equal to or greater than a predefinedvalue,

-   -   wherein said calculation part calculates the biological        information of said organism based on the amount of said        received light when it is detected that said pressure reaches a        level equal to or greater than said predefined value.

A fourteenth aspect of the present invention is the apparatus ofmeasuring biological information using light according to the twelfthaspect of the present invention, comprising a pressure measuring partmeasuring the pressure applied to the surface of said organism by saidforming part,

-   -   wherein the biological information of said organism is        calculated based on the amount of said light received in said        receiving part and said pressure measured in said pressure        measuring part.

A fifteenth aspect of the present invention is the apparatus ofmeasuring biological information using light according to the twelfthaspect of the present invention, wherein the face of the forming partcontacting the surface of the organism is substantially flat.

A sixteenth aspect of the present invention is the apparatus ofmeasuring biological information using light according to the twelfthaspect of the present invention, wherein a protrusion part is providedon the face of the forming part contacting the surface of the organism,and

-   -   the light source part and the light receiving part are provided        on said protrusion part.

A seventeenth aspect of the present invention is the apparatus ofmeasuring biological information using light according to the twelfthaspect of the present invention, wherein said light source part has aplurality of light sources.

An eighteenth aspect of the present invention is the apparatus ofmeasuring biological information using light according to theseventeenth aspect of the present invention, wherein said light sourcepart has said light source provided so that the distance between saidlight source and said light receiving part is a first distance of about15 mm to 30 mm, and said light source provided so that the distancebetween said light source and said light receiving part is asecond-distance of about 35 mm to 80 mm, and

-   -   if the amount of light received in said light receiving part        from said light source with said first distance equals Y1, and        the amount of light received in a light receiving element from        said light source with said second distance equals Y2, said        calculation part calculates the biological information of said        organism using the ratio between said Y2 and said Y1.

A nineteenth aspect of the present invention is the apparatus ofmeasuring biological information using light according to the twelfthaspect of the present invention, wherein said light receiving part has aplurality of light receiving elements.

A twentieth aspect of the present invention is the apparatus ofmeasuring biological information using light according to the nineteenthaspect of the present invention, wherein said light receiving part hassaid light receiving element provided so that the distance between saidlight source part and said light receiving element is a first distanceof 15 mm to 30 mm, and said light receiving element provided so that thedistance between said light source part and said light receiving elementis a second distance of 35 mm to 80 mm, and

-   -   if the amount of light received in said light receiving element        with said first distance equals Y1, and the amount of light        received in said light receiving element with said second        distance equals Y2, said calculation part calculates the        biological information of said organism using the ratio between        said Y2 and said Y1.

A twenty-first aspect of the present invention is the apparatus ofmeasuring biological information using light according to the twelfthaspect of the present invention, comprising:

-   -   a display part displaying said biological information of said        organism calculated in said calculation part;    -   a communication part communicating said biological information        of said organism to and from external apparatuses; and    -   an input part for inputting measurement conditions of said        organism.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of an apparatus of measuring biologicalinformation using light in Embodiment 1 of the present invention;

FIG. 2 shows a graph showing a relation between the amount of receivedlight and the thickness of subcutaneous fat in the apparatus ofmeasuring biological information using light of Embodiment 1 of thepresent invention;

FIG. 3 is a block diagram of the apparatus of measuring biologicalinformation using light having a different shape of a forming part inEmbodiment 1 of the present invention;

FIG. 4 is a block diagram of the apparatus of measuring biologicalinformation using light in Embodiment 2 of the present invention;

FIG. 5 is a top view showing the forming part of the apparatus ofmeasuring biological information using light in Embodiment 2 of thepresent invention;

FIG. 6 is a block diagram of the apparatus of measuring biologicalinformation using light in Embodiment 3 of the present invention;

FIG. 7 is a top view showing the forming part of the apparatus ofmeasuring biological information using light in Embodiment 3 of thepresent invention;

FIG. 8 is a block diagram of the apparatus of measuring biologicalinformation using light in Embodiment 4 of the present invention;

FIG. 9 is a top view showing the forming part of the apparatus ofmeasuring biological information using light in Embodiment 4 of thepresent invention;

FIG. 10 is a block diagram of the apparatus of measuring biologicalinformation using light in Embodiment 5 of the present invention;

FIG. 11 is a top view showing the forming part of the apparatus ofmeasuring biological information using light in Embodiment 5 of thepresent invention;

FIG. 12 is a perspective view showing the forming part of the apparatusof measuring biological information using light in Embodiment 6 of thepresent invention;

FIG. 13 is a block diagram of the apparatus of measuring biologicalinformation using light in Embodiment 6 of the present invention;

FIG. 14 is a block diagram showing a different cross-section of theapparatus of measuring biological information using light in Embodiment6 of the present invention;

FIG. 15 is a block diagram of an apparatus of measuring the thickness ofsubcutaneous fat using light in Embodiment 7 of the present invention;

FIG. 16 is a top view of a forming part of the apparatus of measuringthe thickness of subcutaneous fat using light in Embodiment 7 of thepresent invention, seen from the side on which it contacts the surfaceof the organism;

FIG. 17 is a block diagram of the apparatus of measuring the thicknessof subcutaneous fat using light in which a light source part isdifferent in configuration from a light receiving part in Embodiment 7of the present invention;

FIG. 18 is a top view of the forming part of the apparatus of measuringthe thickness of subcutaneous fat using light in Embodiment 7 of thepresent invention, seen from the side on which it contacts the surfaceof the organism;

FIG. 19 shows a graph showing a relation between the amount of receivedlight for measurement and the thickness of subcutaneous fat determinedby the apparatus of measuring the thickness of subcutaneous fat usinglight in Embodiment 7 of the present invention;

FIG. 20 shows a graph showing a relation between a parameter Y2/Y1 andthe thickness of subcutaneous fat determined by the apparatus ofmeasuring the thickness of subcutaneous fat using light in Embodiment 7of the present invention;

FIG. 21 is a block diagram of the apparatus of measuring the thicknessof subcutaneous fat using light in Embodiment 8 of the presentinvention;

FIG. 22 shows a graph showing a relation between the amount of receivedlight for measurement and the thickness of subcutaneous fat determinedby the apparatus of measuring the thickness of subcutaneous fat usinglight in Embodiment 8 of the present invention;

FIG. 23 shows a graph showing a relation between the parameter Y2/Y1 andthe thickness of subcutaneous fat determined by the apparatus ofmeasuring the thickness of subcutaneous fat using light in Embodiment 8of the present invention;

FIG. 24 shows a block diagram of the apparatus of measuring thethickness of subcutaneous fat using light in Embodiment 9 of the presentinvention;

FIG. 25 is a top view of the forming part of the apparatus of measuringthe thickness of subcutaneous fat using light in Embodiment 9 of thepresent invention, seen from the side on which it contacts the surfaceof the organism;

FIG. 26( a) is a top view of the forming part of the apparatus ofmeasuring the thickness of subcutaneous fat using light in which theforming part is different in shape from a protrusion part in Embodiment9 of the present invention, seen from the side on which it contacts thesurface of the organism;

FIG. 26( b) is a side view of the forming part of the apparatus ofmeasuring the thickness of subcutaneous fat using light in which theforming part is different in shape from the protrusion part inEmbodiment 9 of the present invention, seen from the side on which itcontacts the surface of the organism;

FIG. 27( a) is a top view of the forming part of the apparatus ofmeasuring the thickness of subcutaneous fat using light in which theforming part is different in shape from the protrusion part in,Embodiment 9 of the present invention, seen from the side on which itcontacts the surface of the organism;

FIG. 27( b) is a side view of the forming part of the apparatus ofmeasuring the thickness of subcutaneous fat using light in which theforming part is different in shape from the protrusion part inEmbodiment 9 of the present invention, seen from the side on which itcontacts the surface of the organism;

FIG. 28 shows a graph showing a relation between the amount of receivedlight for measurement and the thickness of subcutaneous fat determinedby the apparatus of measuring the thickness of subcutaneous fat usinglight in Embodiment 9 of the present invention;

FIG. 29 shows a graph showing a relation between the parameter Y2/Y1 andthe thickness of subcutaneous fat determined by the apparatus ofmeasuring the thickness of subcutaneous fat using light in Embodiment 9of the present invention;

FIG. 30 is a block diagram of the apparatus of measuring the thicknessof subcutaneous fat using light in Embodiments 10 and 11 of the presentinvention;

FIG. 31 is a top view of the forming part of the apparatus of measuringthe thickness of subcutaneous fat using light in Embodiments 10 and 11of the present invention, seen from the side on which it contacts thesurface of the organism;

FIG. 32 is a block diagram of the apparatus of measuring the thicknessof subcutaneous fat using light in which the light source part isdifferent in configuration from the light receiving part in Embodiment10 of the present invention;

FIG. 33 is a top view of the forming part of the apparatus of measuringthe thickness of subcutaneous fat using light in Embodiment 10 of thepresent invention, seen from the side on which it contacts the surfaceof the organism;

FIG. 34 shows one example of relation between the thickness ofsubcutaneous fat and a contact force in Embodiment 10 of the presentinvention;

FIG. 35 shows a graph showing one example of relation between the amountof received light for measurement and the thickness of subcutaneous fatdetermined by the apparatus of measuring the thickness of subcutaneousfat using light in Embodiments 10 and 11 of the present invention;

FIG. 36 shows a graph showing one example of relation between the amountof received light for measurement and the thickness of subcutaneous fatwhen the pressure is not controlled in Embodiment 10 of the presentinvention;

FIG. 37 is a graph showing a relation between the parameter Y2/Y1 andthe thickness of subcutaneous fat determined by the apparatus ofmeasuring the thickness of subcutaneous fat using light in Embodiments10 and 11 of the present invention;

FIG. 38 is a block diagram of the conventional subcutaneous fatthickness measuring apparatus;

FIG. 39 is a conceptual view showing a problem in the conventionalsubcutaneous fat thickness measuring apparatus; and

FIG. 40 is a conceptual view showing another problem in the conventionalsubcutaneous fat thickness measuring apparatus.

DESCRIPTION OF SYMBOLS

-   1 surface of organism-   2 light source-   3 measuring light receiving element-   4 skin-   5 subcutaneous fat-   6 muscle-   7 light received by measuring light receiving element-   8 correcting light receiving element-   9 light received by correcting light receiving element-   10 forming part-   11 light source part-   12 light receiving part-   13 light received in light receiving part-   14 calculation part-   15 display part-   16 communication part-   17 input part-   18 protrusion part-   19 first light source part-   20 second light source part-   21 first light receiving part-   22 second light receiving part-   23 third light receiving part-   24, 26 light received in third light receiving part-   25 light received in first light receiving part-   27 light received in second light receiving part-   101 surface of organism-   102 light source-   103 measuring light receiving element-   104 correcting light receiving element-   105 skin-   106 subcutaneous fat-   107 muscle-   108 light received by measuring light receiving element-   109 light received by correcting light receiving element-   110 forming part-   111 light source (light source part)-   112 light receiving part-   113 measuring light receiving element-   114 correcting light receiving element-   115 pressure measuring unit-   116 measuring light source element-   117 correcting light source element-   118 light received by correcting light receiving element-   (light from correcting light source element)-   119 light received by measuring light receiving element (light from    measuring light source element)-   120 calculation part-   121 display part-   122 communication part-   123 input part-   124 pressure detecting part-   125 protrusion part-   201 surface of organism-   202 light source-   203 measuring light receiving element-   204 correcting light receiving element-   205 skin-   206 subcutaneous fat-   207 muscle-   208 light received by measuring light receiving element-   209 light received by correcting light receiving element-   210 forming part-   211 light source (light source part)-   212 light receiving part-   213 measuring light receiving element-   214 correcting light receiving element-   215 pressure detecting part-   216 measuring light source element-   217 correcting light source element-   218 light from correcting light source element-   219 light from measuring light source element-   220 calculation part-   221 display part-   222 communication part-   223 input part

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiments of the present invention will be described below withreference to the drawings.

The apparatus of measuring biological information using light of thepresent invention comprises a light source part of irradiating anorganism, a light receiving part of receiving light outgoing from thesurface of the organism after propagating from the light source partthrough the inside of the organism, a forming part of forming thesurface of the organism into a predetermined shape, and a calculationpart of calculating biological information of the organism based on theamount of light received in the light receiving part.

The face of the forming part contacting the surface of the organism ispreferably flat.

Also, the degree of reflection of the face of the forming partcontacting the surface of the organism is preferably substantially 0.

Also, a protrusion part is preferably provided on the face of theforming part contacting the surface of the organism.

Here, the protrusion part may be provided between the light source partand the light receiving part. In this case, the protrusion part ispreferably located at a distance of about 3 to 30 mm from the lightsource part.

Also, the light source part or/and light receiving part may be providedin the protrusion part.

Here, the protrusion part has preferably a shape such that the organismis deformed so that an area of the surface of the organism having alongitudinal dimension of about 3 to 10 mm and a lateral dimension of 3to 50 mm is concaved to the depth of about 2 to 20 mm.

Also, there may be a plurality of light source parts or/and lightreceiving parts.

Also, the apparatus of measuring biological information using light ofthe present invention preferably has the light source part comprising afirst light source part provided at a first predetermined location ofthe forming part and a second light source part provided at a secondpredetermined location of the protrusion part, and the light receivingpart comprising a first light receiving part provided at a thirdpredetermined location of the forming part opposite to the firstpredetermined location with the protrusion part therebetween and asecond light receiving part provided at a fourth predetermined locationof the protrusion.

In addition, the light receiving part preferably comprises a third lightreceiving part provided at a fifth predetermined location between thesecond predetermined location and the fourth predetermined location.

Here, it is preferable that the distance between the first predeterminedlocation and the protrusion part is in the range of from about 1 to 20mm, and the distance between the protrusion part and the thirdpredetermined location is in the range of from about 1 to 20 mm. Also,it is preferable that the distance between the second predeterminedlocation and the fifth predetermined location is in the range of from 1to 20 mm, and the distance between the second predetermined location andthe fourth predetermined location is in the range of from 20 to 50 mm.

Also, the third light receiving part may be provided at the fifthpredetermined location between the first predetermined location and thethird predetermined location.

Also, preferably, the apparatus of measuring the thickness ofsubcutaneous fat using light of the present invention further comprisesa display part displaying biological information calculated by thecalculation part, a communication part communicating the biologicalinformation to and from external apparatuses, and an input part forinputting measurement conditions.

In the present invention, the biological information includes the levelof subcutaneous fat, the concentration of glucose in an organism and theconcentration of oxygen in an organism. Here, the central wavelength oflight emitted from the light source part is preferably in the range offrom about 450 nm to 1000 nm if the biological information is theconcentration of glucose in the organism, and the central wavelength oflight emitted from the light source part is preferably in the range offrom about 1000 nm to 2000 nm if the biological information is theconcentration of oxygen in the organism.

EMBODIMENT 1

FIG. 1 is a block diagram of an apparatus of measuring biologicalinformation using light in Embodiment 1 of the present invention.

The apparatus of measuring biological information using light in thisembodiment has a light source part 11 and a light receiving part 12placed in a forming part 10 forming the surface of an organism 1 into aflat shape. Here, it is preferable that the forming part 10 is arectangle being 25 mm long and 40 mm wide, and the area of the formingpart 10 is about 1000 mm² or greater, for example, although notspecifically limited. However, the forming part 10 is not necessarily arectangle. The material of the forming part 10 may be any materialhaving a degree of strength such that the shape of the forming part 10is not changed when it is contacted against the surface of the organism1.

The forming part 10 is made of material such as black ABS in which thedegree of reflection of the face contacting the surface of the organism1 is substantially 0 in the range of wavelengths of light emitted fromthe light source part 11. “Substantially 0” in this case refers to adegree of reflection of about 2% or smaller. Furthermore, as anothermethod, the forming part 10 may be coated or painted with a materialwith the degree of reflection of 2% or smaller.

A light source such as an LED light source, laser light source or bulbis incorporated in the light source part 11. The central wavelength oflight outputted from the light source part 11 is in the range of fromabout 500 nm to 1000 nm or from about 1000 nm to 2000 nm. Also, thelight source part 11 may have a configuration in which the light sourceis separated from the surface of the organism 1, and the light is guidedfrom the light source of the surface of the organism 1 by optical fibersor the like.

The light receiving part 12 comprises a light receiving sensor such as aphotodiode, avalanche photodiode or CdS cell. Also, light may be guidedbetween the surface of the organism 1 and the light receiving sensor byoptical fibers or the like.

The calculation part 14 calculates the thickness of subcutaneous fataccording to the amount of light 13 received in the light receiving part12, and the display part 15 displays biological information determinedby the calculation part 14 such as the thickness of subcutaneous fat.Also, the communication part 16 communicates biological informationdetermined by the calculation part 14 such as information of thethickness of subcutaneous fat and control data for start of measurementto and from external apparatuses. Also, by the input part 17,measurement conditions such as the measured site, sex, age, height andweight of a subject may be inputted, and control for start ofmeasurement may be performed.

Operations of the apparatus of measuring biological information usinglight in this embodiment will now be described.

Light emitted from the light source part 11 propagates through a skin 4,a subcutaneous fat 5 and a muscle 6 in the organism while it isscattered and absorbed. Of light propagating through the inside of theorganism, the amount of light 13 received in the light receiving part 12increases with the thickness of the subcutaneous fat 5 due todifferences in light absorption and light scattering characteristicsbetween the skin 4 and the subcutaneous fat 5 and the muscle 6. Therelation between the thickness of the subcutaneous fat 5 and the amountof received light is shown in FIG. 2. A graph of relation shown in FIG.2 is previously determined and stored in the calculation part 14,whereby the thickness of subcutaneous fat can be determined in thecalculation part 14, using the amount of light 13 received in the lightreceiving part 12. In the calculation part 14, the percent of body ofthe subject can be calculated from measurement conditions and thethickness of subcutaneous fat inputted by the input part 17 and thecommunication part 16. Also, a plurality of measurement conditions maybe stored in advance.

In this operation, the surface of the organism 1 is formed into a flatshape by the forming part 10, whereby a change in propagation of lightin association with a local change in shape of the surface of theorganism 1 can be controlled. Also, the area of the forming part 10 hasa certain area that allows the force exerted by abutting the formingpart 10 against the surface of the organism 1 to be scattered over thearea, thus preventing a situation in which the organism is deformed foreach measurement due to variations in the force exerted by the formingpart 10 being contacted against the surface of the organism 1. By theseeffects, the shape of the organism can be kept constant, and thereforevariations in the shape of the organism for each measurement can beprevented, thus making it possible to carry out measurements with highaccuracy. Furthermore, it is not necessarily required to form thesurface of the organism 1 into a flat shape, and even if the area of theforming part 10 contacting the organism is concaved as shown in FIG. 3for example, the shape of the organism can be kept constant, andtherefore measurements can be carried out with high reproducibility.

Also, the degree of reflection of the face of the forming part 10contacting the surface of the organism 1 is almost 0, thereby making itpossible to prevent a situation in which light going out of the organismthrough the surface of the organism 1 goes back into the organism. Thus,of light 13 received in the light receiving part 12, the amount ofcomponent propagating through a shallow area in the organism, can bereduced, and therefore correlation between the amount of received lightand the thickness of subcutaneous fat is improved.

Also, the wavelength of the light source part 11 can be selected to meetthe absorption band of a substance of interest, and light receptioncharacteristics of the light receiving part 12 can be selected to meetthe absorption band of the substance of interest, thereby making itpossible to measure the concentration of oxygen in the organism and theconcentration of glucose in the organism by the amount of receivedlight. In the case of the concentration of oxygen in the organism, thelight source part 11 having a light source element of two wavelengths: awavelength of about 450 nm to 800 nm and a wavelength of about 800 nm to1000 nm is used, or the light receiving part 12 comprising two or morelight receiving sensors having sensitivity characteristics in twowavelengths: a wavelength of about 450 nm to 800 nm and a wavelength ofabout 800 nm to 1000 nm is provided, thereby making it possible tomeasure the concentration of oxygen in the organism with high accuracyas in the case of the subcutaneous fat 5. Also, as for the concentrationof glucose in the organism, the light source part 11 constituted by alight source element of a wavelength of about 1000 nm to 2000 nm and thelight receiving part 12 constituted by a light receiving sensor having asensitivity in a wavelength of about 1000 nm to 2000 nm are used,thereby making it possible to carry out measurements with high accuracy.

EMBODIMENT 2

FIG. 4 is a block diagram of the apparatus of measuring biologicalinformation using light in Embodiment 2 of the present invention. Also,FIG. 5 shows the forming part 10 seen from the above. The protrusionpart 18 that is 5 mm wide, 50 mm long and 5 mm high is provided betweenthe light source part 11 and the light receiving part 12 on the formingpart 10 flatting the surface of the organism 1.

Here, it is preferable that the forming part 10 is a rectangle beingabout 25 mm long and 40 mm wide, and the area of the forming part 10 is1000 mm² or greater, for example, although not specifically limited.However, the forming part 10 is not necessarily a rectangle. Thelongitudinal, lateral and vertical dimensions of the protrusion part 18are not necessarily limited to the above values.

The forming part 10 and the protrusion part 18 are made of material suchas black ABS in which the degree of reflection of the face contactingthe surface of the organism 1 is substantially 0 in the range ofwavelengths of light emitted from the light source part 11.“Substantially 0” in this case refers to a degree of reflection of about2% or smaller. Furthermore, as another method, the forming part 10 maybe coated or painted with a material with the degree of reflection ofabout 2% or smaller.

The surface of the organism 1 is deformed because it is pressed by theforming part 10 and the protrusion part 18. However, because the widthof the protrusion part 18 is small, the surface of the organism 1 isdeformed such that only the portion just below the protrusion part 18 ofthe subcutaneous fat 5, which is the softest of organic tissues, ispushed out to the area where the protrusion part 18 does not exist asshown in FIG. 4, and only the thickness of the subcutaneous fat 5 islocally changed in the organism.

The light source part 11, the light receiving part 12, the calculationpart 14, the display part 15, the communication part 16 and the inputpart 17 of the apparatus of measuring biological information using lightin this embodiment have configurations and functions similar to those ofthe apparatus of measuring biological information using light inEmbodiment 1.

According to the apparatus of measuring biological information usinglight in this embodiment, because the surface of the organism 1 isformed into a flat shape by the forming part 10, and the degree ofreflection of the face of the forming part 10 contacting the surface ofthe organism 1 is almost 0, the same effects as those of the apparatusof measuring biological information using light in Embodiment 1 can beobtained.

In addition, in the example of prior art, the distance between the lightsource part 11 and the light receiving part 12 should be increased forobtaining information of a deeper area in the organism, but in thisembodiment, light that has propagated through a shallow area near thesurface of the organism 1 is prevented from propagating to the lightreceiving part 12 by the protrusion part 18, and therefore a largeramount of component of light that has propagated through a deeper areain the organism is received in the light receiving part 12 compared tothe case where the protrusion part 18 is not provided. Consequently, thelight received in the light receiving part 12 has a larger amount ofinformation of the thickness of the subcutaneous fat 5 compared to thecase where the protrusion part 18 is not provided. Thus, only the lightthat has propagated through a deeper area in the organism can bereceived without increasing the distance between the light source part11 and the light receiving part 12. As a result, the measurement opticalsystem can be downsized. In addition, the area of the organism to bemeasured decreases, and thereby the influence of local variations inthickness of tissues can be alleviated, resulting in improvedmeasurement accuracy. In other words, the area through which lightpasses decreases, and thereby the measurement accuracy is improved.

Also, as in the case of Embodiment 1, the wavelength of the light sourcepart 11 can be selected to meet the absorption band of a substance ofinterest, and light reception characteristics of the light receivingpart 12 can be selected to meet the absorption band of the substance ofinterest, thereby making it possible to measure the concentration ofoxygen in the organism and the concentration of glucose in the organismby the amount of received light.

EMBODIMENT 3

FIG. 6 is a block diagram of the apparatus of measuring biologicalinformation using light in Embodiment 3 of the present invention. Also,FIG. 7 shows the forming part 10 seen from the above. The apparatus ofmeasuring biological information using light in this embodiment has theprotrusion part 18 being 5 mm long, 50 mm wide and 5 mm high on theforming part 10 forming the surface of the organism 1 into a flat shape.

Here, it is preferable that the forming part 10 is a rectangle beingabout 25 mm long and 40 mm wide, and the area of the forming part 10 is1000 mm² or greater, for example, although not specifically limited.However, the forming part 10 is not necessarily a rectangle. Thelongitudinal, lateral and vertical dimensions of the protusion part 18are not necessarily limited to the above values. The light source part11 and the light receiving part 12 are placed in the protusion part 18.

The surface of the organism is deformed because it is pressed by theforming part 10 and the protrusion part 18. However, because the widthof the protrusion part 18 is small, the surface of the organism 1 isdeformed such that only the softest portion just below the protrusionpart 18 of the subcutaneous fat 5 is pushed out to the area where theprotrusion part 18 does not exist as shown in FIG. 6, and only thethickness of the subcutaneous fat 5 is locally changed.

The forming part 10 and the protrusion part 18 are made of material suchas black ABS in which the degree of reflection of the face contactingthe surface of the organism 1 is substantially 0 in the range ofwavelengths of light emitted from the light source part. “Substantially0” in this case refers to a degree of reflection of 2% or smaller.Furthermore, as another method, the forming part 10 may be coated orpainted with a material with the degree of reflection of 2% or smaller.

The light source part 11, the light receiving part 12, the calculationpart 14, the display part 15, the communication part 16 and the inputpart 17 of the apparatus of measuring biological information using lightin this embodiment have configurations and functions similar to those ofthe apparatus of measuring biological information using light inEmbodiment 1.

According to the apparatus of measuring biological information usinglight in this embodiment, because the surface of the organism 1 isformed into a flat shape by the forming part 10, and the degree ofreflection of the face of the forming part 10 contacting the surface ofthe organism 1 is almost 0, the same effects as those of the apparatusof measuring biological information using light in Embodiment 1 can beobtained.

In addition, due to the presence of the light source part 11 and thelight receiving part in the protrusion part 18, the thickness of thesubcutaneous fat 5 through which light substantially propagates isreduced compared to the actual thickness by a level equivalent to theheight of the protrusion part 18. As the thickness of the subcutaneousfat 5 to be measured increases, the distance between the light sourcepart 11 and the light receiving part 12 should be increased, andtherefore conversely, by making the subcutaneous fat 5 thinner, thedistance between the light source 11 and the light receiving part 12 canbe reduced. Then, the original thickness of subcutaneous fat can becalculated by adding a thickness equivalent to the protrusion part 18 tothe measured thickness of subcutaneous fat. That is, the distancebetween the light source part 11 and the light receiving part 12 can bereduced compared to the case where the protrusion part 18 is notprovided. As a result, the measurement optical system can be downsized.In addition, the area of the organism to be measured decreases, andthereby the influence of local variations in thickness of tissues can bealleviated, resulting in improved measurement accuracy.

Also, as in the case of Embodiment 1, the wavelength of the light sourcepart 11 can be selected to meet the absorption band of a substance ofinterest, and light reception characteristics of the light receivingpart 12 can be selected to meet the absorption band of the substance ofinterest, thereby making it possible to measure the concentration ofoxygen in the organism and the concentration of glucose in the organismby the amount of received light.

EMBODIMENT 4

FIG. 8 is a block diagram of the apparatus of measuring biologicalinformation using light in Embodiment 4 of the present invention. Also,FIG. 9 shows the forming part 10 seen from the above. The apparatus ofmeasuring biological information using light in this embodiment has theprotrusion part 18 being 5 mm long, 5 mm wide and 5 mm high and thelight receiving part 12 on the forming part 10 forming the surface ofthe organism 1 into a flat shape.

Here, it is preferable that the forming part 10 is a rectangle beingabout 25 mm long and 40 mm wide, and the area of the forming part 10 is1000 mm² or greater, for example, although not specifically limited.However, the forming part 10 is not necessarily a rectangle. Thelongitudinal, lateral and vertical dimensions of the protrusion part 18are not necessarily limited to the above values. The light source part11 is placed in the protrusion part 18.

The surface of the organism 1 is deformed because it is pressed by theforming part 10 and the protrusion part 18. However, because the widthof the protrusion part 18 is small, the surface of the organism 1 isdeformed such that only the portion just below the protrusion part 18 ofthe subcutaneous fat 5 is pushed out to the area where the protrusionpart 18 does not exist as shown in FIG. 8, and only the thickness of thesubcutaneous fat 5 is locally changed.

The forming part 10 and the protrusion part 18 are made of material suchas black ABS in which the degree of reflection of the face contactingthe surface of the organism 1 is substantially 0 in the range ofwavelengths of light emitted from the light source part. “Substantially0” in this case refers to a degree of reflection of about 2% or smaller.Furthermore, as another method, the forming part 10 may be coated orpainted with a material with the degree of reflection of about 2% orsmaller.

The light source part 11, the light receiving part 12, the calculationpart 14, the display part 15, the communication part 16 and the inputpart 17 of the apparatus of measuring biological information using lightin this embodiment have configurations and functions similar to those ofthe apparatus of measuring biological information using light inEmbodiment 1.

According to the apparatus of measuring biological information usinglight in this embodiment, because the surface of the organism 1 isformed into a flat shape by the forming part 10, and the degree ofreflection of the face of the forming part 10 contacting the surface ofthe organism 1 is almost 0, the same effects as those of the apparatusof measuring biological information using light in Embodiment 1 can beobtained.

In addition, due to the presence of the light source part 11 in theprotrusion part 18, the depth of the area in the organism through whichlight substantially propagates is increased by a level equivalent to theheight of the protrusion part 18. Thus, a larger amount of component oflight that has propagated through a deeper area in the organism isreceived in the light receiving part 12, compared to the case where theprotrusion part 18 is not provided. Consequently, the light received inthe light receiving part 12 has a larger amount of information of thethickness of the subcutaneous fat 5 compared to the case where theprotrusion part 18 is not provided. Therefore, only the light that haspropagated through a deeper area in the organism can be received withoutincreasing the distance between the light source part 11 and the lightreceiving part 12, thus making it possible to downsize the measurementoptical system. In addition, the area of the organism to be measureddecreases, and thereby the influence of local variations in thickness oftissues can be alleviated, resulting in improved measurement accuracy.

Also, as in the case of Embodiment 1, the wavelength of the light sourcepart 11 can be selected to meet the absorption band of a substance ofinterest, and light reception characteristics of the light receivingpart 12 can be selected to meet the absorption band of the substance ofinterest, thereby making it possible to measure the concentration ofoxygen in the organism and the concentration of glucose in the organismby the amount of received light.

EMBODIMENT 5

FIG. 10 is a block diagram of the apparatus of measuring biologicalinformation using light in Embodiment 5 of the present invention. Also,FIG. 11 shows the forming part 10 seen from the above. Here, it ispreferable that the forming part 10 is a rectangle being 25 mm long and40 mm wide, and the area of the forming part 10 is about 1000 mm² orgreater, for example, although not specifically limited. However, theforming part 10 is not necessarily a rectangle. In addition, theprotrusion part 18 being about 5 mm long, 5 mm wide and 5 mm high andthe light source part 11 are provided on the forming part 10 forming thesurface of the organism 1 into a flat shape. The longitudinal, lateraland vertical dimensions of the protrusion part 18 are not necessarilylimited to the above values. Also, the light receiving part 12 is placedon the protrusion part 18.

The surface of the organism is deformed because it is pressed by theforming part 10 and the protrusion part 18. However, because the widthof the protrusion part 18 is small, the surface of the organism 1 isdeformed such that only the softest portion just below the protrusionpart 18 of the subcutaneous fat 5 is pushed out to the area where theprotrusion part 18 does not exist as shown in FIG. 10, and only thethickness of the subcutaneous fat 5 is locally changed.

The forming part 10 and the protrusion part 18 are made of material suchas black ABS in which the degree of reflection of the face contactingthe surface of the organism 1 is substantially 0 in the range ofwavelengths of light emitted from the light source part. “Substantially0” in this case refers to a degree of reflection of about 2% or smaller.Furthermore, as another method, the forming part 10 may be coated orpainted with a material with the degree of reflection of about 2% orsmaller.

The light source part 11, the light receiving part 12, the calculationpart 14, the display part 15, the communication part 16 and the inputpart 17 of the apparatus of measuring biological information using lightin this embodiment have configurations and functions similar to those ofthe apparatus of measuring biological information using light inEmbodiment 1.

According to the apparatus of measuring biological information usinglight in this embodiment, because the surface of the organism 1 isformed into a flat shape by the forming part 10, and the degree ofreflection of the face of the forming part 10 contacting the surface ofthe organism 1 is almost 0, the same effects as those of the apparatusof measuring biological information using light in Embodiment 1 can beobtained.

In addition, due to the presence of the light receiving part 12 in theprotrusion part 18, the depth of the area in the organism through whichlight substantially propagates is increased by a level equivalent to theheight of the protrusion part 18. Thus, a larger amount of component oflight that has propagated through a deeper area in the organism isreceived in the light receiving part 12, compared to the case where theprotrusion part 18 is not provided. Consequently, the light received inthe light receiving part 12 has a larger amount of information of thethickness of the subcutaneous fat 5 compared to the case where theprotrusion part 18 is not provided. Therefore, only the light that haspropagated through a deeper area in the organism can be received withoutincreasing the distance between the light source part 11 and the lightreceiving part 12, thus making it possible to downsize the measurementoptical system. In addition, the area of the organism to be measureddecreases, and thereby the influence of local variations in thickness oftissues can be alleviated, resulting in improved measurement accuracy.

Also, as in the case of Embodiment 1, the wavelength of the light sourcepart 11 can be selected to meet the absorption band of a substance ofinterest, and light reception characteristics of the light receivingpart 12 can be selected to meet the absorption band of the substance ofinterest, thereby making it possible to measure the concentration ofoxygen in the organism and the concentration of glucose in the organismby the amount of received light.

EMBODIMENT 6

FIG. 12 is a perspective view of the forming part 10 of the apparatus ofmeasuring biological information using light in Embodiment 5 of thepresent invention.

The forming part 10 is substantially flat, and the protrusion part 18 isplaced at almost the center thereof. The forming part 10 has a circularshape with the diameter of about 60 mm. The protrusion part 18 is about5 mm long, 50 mm wide and 5 mm high. Here, the forming part 10 does notnecessarily have a circular shape, and its area is preferably about 1000mm² or greater. Also, the longitudinal, lateral and vertical dimensionsof the protrusion part 18 are not necessarily limited to the abovevalues.

A first light source part 19 is placed on an area of the forming part 10excluding the protrusion part 18 and at a distance of about 15 mm fromthe center of the protrusion part 18 (at first predetermined location),and a second light source part 20 is placed at one end of the protrusionpart 18 and at a distance of about 15 mm from the center of theprotrusion part 18 (second predetermined location). A first lightreceiving part 21 is placed at a distance of about 15 mm from the centerof the protrusion part 18 (at third predetermined location) on the sideopposite to the first light source part 19, a second light receivingpart 22 is placed on the side opposite to the second light source on theprotrusion part 18 and at a distance of about 15 mm from the center ofthe protrusion part 18 (at fourth predetermined location), and a thirdlight receiving part 23 is placed at the center of the protrusion part18 (at fifth predetermined location). Here, the locations of the lightsource parts and the light receiving parts are not necessarily limitedto the above values.

Also, FIGS. 13 and 14 are block diagrams of the apparatus of measuringbiological information using light in this embodiment. FIG. 13 is asectional view taken along the A-a line when the forming part 10 iscontacted against the surface of the organism 1, and similarly FIG. 14is a sectional view taken along the B-b line when the forming part 10 iscontacted against the surface of the organism 1.

The surface of the organism 1 is deformed because it is pressed by theforming part 10 and the protrusion part 18. However, because the widthof the protrusion part 18 is small, the surface of the organism 1 isdeformed such that only the portion just below the protrusion part 18 ofthe subcutaneous fat 5 is pushed out to the area where the protrusionpart 18 does not exist as shown in FIGS. 13 and 14, and only thethickness of the subcutaneous fat 5 is locally changed.

The forming part 10 and the protrusion part 18 are made of material suchas black ABS in which the degree of reflection of the face contactingthe surface of the organism 1 is substantially 0 in the range ofwavelengths of light emitted from the first light source part 19 and thesecond light source part 20. “Substantially 0” in this case refers to adegree of reflection of 2% or smaller. Furthermore, as another method,the forming part 10 may be coated or painted with a material with thedegree of reflection of about 2% or smaller.

A light source such as an LED light source, laser light source or bulbis incorporated in each of the first light source part 19 and secondlight source part 20. The central wavelength of light outputted from thefirst light source part 19 and the second light source part 20 is in therange of from about 500 nm to 1000 nm or from about 1000 nm to 2000 nm.Also, the first light source part 19 and the second light source part 20may have a configuration in which the light source is separated from thesurface of the organism 1, and light is be guided from the light sourceto the surface of the organism 1 by the optical fibers or the like.

The first light receiving part 21, the second light receiving part 22and the third light receiving part 23 each comprise a light receivingsensor such as a photodiode, avalanche photodiode or CdS cell. Also,each of the light receiving parts may have a configuration in whichlight is guided between the surface of the organism 1 and the lightreceiving sensor by optical fibers or the like.

The calculation part 14 calculates the thickness of subcutaneous fataccording to the amount of light received in the light receiving part21, the light receiving part 22 and the third light receiving part 23,and the display part 15 displays the thickness of subcutaneous fat orthe like as biological information determined by the calculation part14. Also, the communication part 16 communicates information of thethickness of subcutaneous fat as biological information determined bythe calculation part 14 and control data such as start of measurement toand from external apparatuses. Also, by the input part 17, measurementconditions such as the measured site, sex, age, height and weight of asubject may be inputted, and control such as start of measurement may beperformed.

Operations of the apparatus of measuring biological information usinglight in this embodiment will be described.

In FIG. 13, light emitted from the first light source part 19 propagatesthrough the skin 4, the subcutaneous fat 5 and the muscle 6 while it isscattered and absorbed. By carrying out measurements using an amount oflight 24 received in the third light receiving part 23, of light thathas propagated through the inside of the organism, the same effects asthose of Embodiment 5 can be obtained. Also, by using an amount of light25 received in the first light receiving part 21, of light that haspropagated through the inside of the organism, only the light that haspropagated through a deeper area in the organism can be received withoutincreasing the distance between the first light source part 19 and thefirst light receiving part 21 as in the case of Embodiment 2, thusmaking it possible to downsize the measurement optical system. Inaddition, the area of the organism to be measured decreases, and therebythe influence of local variations in thickness of tissues can bealleviated, resulting in improved measurement accuracy. In addition, bymaking corrections in the same manner as the example of prior art usinglight received in the third receiving part 23 provided in the protrusionpart 18, measurements can be carried out with high accuracy.

In FIG. 14, light emitted from the second light source part 20propagates through the skin 4, the subcutaneous fat 5 and the muscle 6while it is scattered and absorbed. Speaking of amounts of light 26received in the third light receiving part 23 and light 27 received inthe second light receiving part 22, of light that has propagated throughthe inside of the organism, only the light that has propagated through adeeper area in the organism can be received without increasing thedistance between the second light source part 20 and the third andsecond light receiving parts 23 and 22 as in the case of Embodiment 3,thus making it possible to downsize the measurement optical system. Inaddition, the area of the organism to be measured decreases, and therebythe influence of local variations in thickness of tissues can bealleviated, resulting in improved measurement accuracy. In addition, bymaking corrections in the same manner as the example of prior art usinglight received in the third receiving part 23 provided in the protrusionpart 18, measurements can be carried out with high accuracy.

Also, by averaging in the calculation part 14 the thicknesses ofsubcutaneous fat determined by carrying out these two measurements atthe same time, more accurate measurements can be carried out.

Also, as in the case of Embodiment 1, the wavelengths of the first lightsource part 19 and the second light source part 20 can be selected tomeet the absorption band of a substance of interest, and light receptioncharacteristics of the light receiving part 21, the second lightreceiving part 22 and the third light receiving part 23 can be selectedto meet the substance of interest, thereby making it possible to measurethe concentration of oxygen in the organism and the concentration ofglucose in the organism by the amount of received light.

The method of measuring the thickness of subcutaneous fat using light inone embodiment of the present invention is characterized by comprising astep A of shaping the surface of an organism into a predetermined shapeby applying a pressure thereto, a step B of measuring the pressure, astep C of irradiating the organism with light, a step D of receivinglight propagating through the inside of the organism and outgoing fromthe surface of the organism, and a step E of calculating the thicknessof subcutaneous fat of the organism based on the amount of lightreceived in the step D and the pressure measured in the step B. In thisway, influences based on the change in the thickness of subcutaneous fatand the change in the amount of blood in the subcutaneous fat by thepressure applied to the surface of the organism are eliminated, therebymaking it possible to measure the thickness of subcutaneous fat withhigh reproducibility and accuracy.

Also, the method of measuring the thickness of subcutaneous fat usinglight in another embodiment of the present invention is characterized bycomprising a step A of shaping the surface of an organism into apredetermined shape by applying a pressure thereto, a step B ofdetecting that the pressure reaches a predefined value, a step C ofirradiating the organism with light, a step D of receiving lightpropagating through the inside of the organism and outgoing from thesurface of the organism when it is detected in the step B that thepressure reaches the predefined value, and a step E of calculating thethickness of subcutaneous fat of the organism based on the amount oflight received in the step D. The thickness of subcutaneous fatdecreases as the pressure applied to the surface of the organismincreases, but the thickness converges at a certain value. When thepressure at which the thickness of subcutaneous fat converges is definedas the predefined value, by applying a pressure equal to or greater thanthe predefined value, measurements can be carried out while thickness ofsubcutaneous fat is kept stable, and therefore the thickness ofsubcutaneous fat can be measured with high reproducibility and accuracy.

Here, if the predefined value in the step B is equal to or greater thanabout 1 kg, the thickness of subcutaneous fat is advantageouslystabilized.

Also, if the central wavelength of light applied in the step C is in therange of from about 500 nm to 1000 nm, differences in absorption andscattering characteristics are advantageously large between respectivetissues of skin and subcutaneous fat and muscle.

The apparatus of measuring the thickness of subcutaneous fat using lightin one embodiment of the present invention is characterized bycomprising a light source part irradiating an organism, a lightreceiving part receiving light propagating from the light source partthrough the inside of the organism and outgoing from the surface of theorganism, a forming part forming the surface of the organism into apredetermined shape, a pressure measuring part measuring a pressureapplied to the surface of the organism by the forming part, and acalculation part calculating the thickness of subcutaneous fat of theorganism based on the amount of light received in the light receivingpart and the pressure measured in the pressure measuring part. In thisway, influences based on the change in the thickness of subcutaneous fatand the change in the amount of blood in the subcutaneous fat by thepressure applied to the surface of the organism are eliminated, therebymaking it possible to measure the thickness of subcutaneous fat withhigh reproducibility and accuracy.

Also, the apparatus of measuring the thickness of subcutaneous fat usinglight in another embodiment of the present invention is characterized bycomprising a light source part irradiating an organism, a lightreceiving part receiving light propagating from the light source partthrough the inside of the organism and outgoing from the surface of theorganism, a forming part forming the surface of the organism into apredetermined shape, a pressure detecting part detecting that thepressure applied to the surface of the organism by the forming partreaches a predefined value, and a calculation part calculating thethickness of subcutaneous fat of the organism based on the amount oflight received in the light receiving part when the pressure detectingpart detects that the pressure reaches the predefined value. In thisway, the pressure at which the thickness of subcutaneous fat convergesis defined as a predefined value, and a pressure equal to or greaterthan the predefined value is applied to the surface of the organism,whereby measurements can be carried out while the thickness ofsubcutaneous fat is kept stable, thus making it possible to measure thethickness of subcutaneous fat with high reproducibility and accuracy.

Here, if the face of the forming part contacting the surface of theorganism is almost flat, the pressure is advantageously applieduniformly to the surface of the organism which is the area to bemeasured.

Also, it is preferable that a protrusion part is provided on the face ofthe forming part contacting the surface of the organism, and the lightsource part and the light receiving part are provided in the protrusionpart.

Also, a plurality of light sources are preferably provided in the lightsource part. Also, a plurality of light receiving elements may beprovided in the light receiving part.

Also, if there area light source and a light receiving element providedso that the distance between the light source and the light receivingelement is a first distance of about 15 mm to 30 mm, and a light sourceand a light receiving element provided so that the distance between thelight source and the light receiving element is a second distance ofabout 35 mm to 80 mm, and the amount of received light in the lightreceiving element located at the first distance from the light sourceequals Y1, and the amount of received light in the light receivingelement located at the second distance from the light source equals Y2,the thickness of subcutaneous fat of the organism is preferablycalculated using the value of Y2/Y1 in the calculation part. In thisway, influences of blood flows in the skin and the subcutis can beeliminated, thus making it possible to measure the thickness ofsubcutaneous fat with higher reproducibility and accuracy.

The method of measuring the thickness of subcutaneous fat of the presentinvention and the apparatus for use in the method will be described indetail below using the drawings.

EMBODIMENT 7

FIG. 15 is a block diagram of the apparatus of measuring the thicknessof subcutaneous fat using light in Embodiment 7 of the presentinvention, and FIG. 16 is a top view of a forming part 110 of theapparatus of measuring the thickness of subcutaneous fat using light,seen from the side on which the forming part 110 contacts the surface ofan organism 101.

The forming part 110 forming the surface of the organism 101 into a flatshape is provided on the surface of the organism 101 constituted bythree layers of a skin 105, a subcutaneous fat 106 and a muscle 107. Theforming part 110 has a disk shape with the diameter of 60 mm, and ismade of black ABS. Furthermore, the material of the forming part 110 isnot limited as long as it has a low degree of reflection of light fromthe light source. The forming part 110 has each corner rounded toprevent a situation in which a sharp-pointed portion abuts against thesurface of the organism. Furthermore, the forming part 110 may have anoval shape or a shape of a flat plate whose corner is chamfered that isabout 40 mm long and 60 mm wide.

A light source part constituted by a light source 111 and a lightreceiving part 112 are provided in the forming part 110. The lightreceiving part 112 is composed of a measuring light receiving element113 and a correcting light receiving element 114. The distance betweenthe measuring light receiving element 113 and the light source 111 isabout 45 mm, and the distance between the correcting light receivingelement 114 and the light source 111 is about 22.5 mm. The emissionorifice of light emitted from the light source 111 has a diameter ofabout 1.5 mmφ, and the incident orifice of light of the measuring lightreceiving element 113 and correcting light receiving element 114 has adiameter of 1.5 mmφ. Furthermore, the distance between the measuringlight receiving element 113 and the light source 111 is preferably inthe range of from about 35 mm to 80 mm (second distance), and thedistance between the correcting light receiving element 114 and thelight source 111 (first distance) is preferably in the range of fromabout 15 mm to 30 mm. When the light source 111 is litup, an amount ofreceived light for correction (amount of received light in the firstdistance Y1) is received in the correcting light receiving element 114,and an amount of received light for measurement (amount of receivedlight in the second distance Y2) is received in the measuring lightreceiving element 113.

Here, the light source 111 uses a laser diode with the centralwavelength about 785 nm as a light source element. Furthermore, thelight source element is preferably a light source element such as alaser diode or LED with the central wavelength of about 500 nm to 1000nm. In addition, if a light guide component such as optical fibers isused for guiding light from the light source element to the surface ofthe organism, heat generated in the light source element isadvantageously prevented from being transferred to the surface of theorganism.

The light receiving part 112 uses a photodiode as a light receivingelement. Furthermore, the light receiving element may be a photoelectricconversion element such as CdS. Also, a light guide component such asoptical fibers may be used for guiding light from the surface of theorganism to the light receiving element.

A pressure measuring part 115 measuring a pressure applied to thesurface of the organism 101 is connected to the forming part 110.

The calculation part 120 calculates the thickness of the subcutaneousfat 106 based on the amount of received light determined in the lightreceiving part 112 and the pressure determined in the pressure measuringpart 115. The calculated thickness of the subcutaneous fat 106 isdisplayed on a display part 121, and is transmitted through acommunication part 122 to other apparatuses as data.

Also, by inputting data such as the height, the weight, the age, the sexand the site to be measured directly from an input part 123 or fromother apparatus through the communication part 122, the percent of bodyfat correlative with the thickness of the subcutaneous fat 6 can becalculated in the calculation part 120 and displayed on the display part121, and data can be transferred to other apparatuses by thecommunication part.

The procedure of measurement will now be described. As a firstoperation, the forming part 110 is contacted against the surface of theorganism 101 while the light source 111 is unlit.

As a second operation, if the amount of light received in the lightreceiving part 112 is about 100 pW or smaller, and the value of acontact force measured in the pressure measuring part 115 is about 0.1kg or greater (about 0.35 kPa or greater when converted to pressurebecause the forming part 111 has a disk shape with the diameter of about60 mm), the light source 111 is lit up when it is ensured that theentire light receiving part 112 contacts the surface of the organism andthe forming part 110 is contacted against the surface of the organism,and in this state, a signal for start of measurement is inputted fromthe communication part 122 or input part 123.

As a third operation, the amount of received light for correction (Y1)is determined by measuring light 118 arriving at the correcting lightreceiving element 114, and the amount of received light for measurement(Y2) is determined by measuring light 119 arriving at the measuringlight receiving element 113.

The method for calculating the thickness of the subcutaneous fat 106 inthe calculation part 120 will now be described. The relation between theamount of received light for measurement and the thickness of thesubcutaneous fat 106 at contact forces of about 0.5 kg (about 1.75 kPaor greater when converted to pressure because the forming part 110 has adisk shape with the diameter of about 60 mm) and about 2.5 kg (8.75 kPaor greater when converted to pressure because the forming part 110 has adisk shape with the diameter of about 60 mm) is shown in FIG. 19. InFIG. 19, the black circle shows the relation between the amount ofreceived light for measurement and the thickness of the subcutaneous fat106 at about 1.75 kPa, and the white circle shows the relation betweenthe amount of received light for measurement and the thickness of thesubcutaneous fat 106 at about 8.75 kPa. Also, the solid line is aprimary regression line for the pressure of about 1.75 kPa, and thedotted line is a primary regression line for the pressure of about 8.75kPa.

Here, the thickness of subcutaneous fat in FIG. 19 refers to thethickness of subcutaneous fat when the subcutaneous fat is pushed by theforming part 110 and consequently crushed. However, the thickness ofsubcutaneous fat in FIG. 19 does not necessarily refer to the thicknessof subcutaneous fat when the subcutaneous fat is pushed by the formingpart 110 and consequently crushed. The thickness of subcutaneous fat mayrefer to the thickness of subcutaneous fat when the subcutaneous fat isnot pushed by the forming part 110, namely the thickness of subcutaneousfat in a natural state. That is, if the relation between the amount ofreceived light and the thickness of subcutaneous fat in a natural stateis determined in advance, the thickness of the subcutaneous fatremaining in a natural state can be determined from the amount ofreceived light. In addition, in Embodiments other than Embodiment 7, thethickness of subcutaneous fat refers to the thickness of subcutaneousfat when the subcutaneous fat is pushed by the forming part andconsequently crushed, but the thickness of subcutaneous fat in a naturalstate may be shown as the thickness of subcutaneous fat by determiningin advance the relation between the thickness of subcutaneous fat in anatural state and the amount of received light. Thus, the thickness ofsubcutaneous fat in Embodiment 7 and in Embodiments other thanEmbodiment 7 refers to the thickness of subcutaneous fat when thesubcutaneous fat is pushed by the forming part and consequently crushed,but may refer to the thickness of subcutaneous fat in a natural statewithout being limited thereto.

As apparent from the figure, the line showing the relation between theamount of received light for measurement and the thickness of thesubcutaneous fat 106 varies depending on the difference in pressureapplied to the surface of the organism. Thus, a plurality of primaryregression lines showing the relation between the amount of receivedlight for measurement and the thickness of subcutaneous fat aredetermined in advance for a plurality of cases with different pressuresapplied to the surface of the organism, a primary regression lineappropriate to the value of pressure measured in the pressure measuringpart 115 is selected from the plurality of primary regression lines, andthe selected primary regression line and the measured amount of receivedlight for measurement are used, whereby the thickness of subcutaneousfat can be measured with high reproducibility and accuracy.

However, influences of variations in scattering and absorption in theskin 105 are included in the amount of received light for measurement aserror factors. The amount of received light for correction is used forcorrecting the influences of the skin 105.

The relation between a parameter Y2/Y1 with the amount of received lightfor measurement (amount of received light in the second distance Y2)divided by the amount of received light for correction (amount ofreceived light in the first distance Y1) and the thickness of thesubcutaneous fat 106 is shown in FIG. 20. In FIG. 20, the black circleshows the relation between Y2/Y1 and the thickness of the subcutaneousfat 106 at about 1.75 kPa, and the white circle shows the relationbetween Y2/Y1 and the thickness of the subcutaneous fat 106 at about8.75 kPa. Also, the solid line is a primary regression line for thepressure of about 1.75 kPa, and the dotted line is a primary regressionline for the pressure of about 8.75 kPa.

When compared with FIG. 19, variations are apparently alleviated, and itcan be thus understood that the amount of received light for correctionbrings about a certain effect of correction. Also, as in the case ofFIG. 19, the line showing the relation between Y2/Y1 and the thicknessof the subcutaneous fat 106 varies depending on the difference inpressure. Thus, as in the case of using only the amount of receivedlight for measurement, a plurality of primary regression lines eachshowing the correlation between Y2/Y1 and the thickness of subcutaneousfat are determined in advance for a plurality of cases of differentpressures applied to the surface of the organism, a primary regressionline appropriate to the value of pressure measured in the pressuremeasuring part 115 is selected from the plurality of primary regressionlines, and by using the selected primary regression line and the Y2/Y1influences of the skin 105 and influences of pressure applied to thesurface of the organism can be corrected, thus making it possible tomeasure the thickness of subcutaneous fat with higher reproducibilityand accuracy.

Here, the light source part is constituted by one light source 111, andthe light receiving part 112 is constituted by the measuring lightreceiving element 113 and the correcting light receiving element 114,but as shown in the block diagram of FIG. 17 and the top view of theforming part 110 of FIG. 18, the light receiving part 112 maybeconstituted by one light receiving element, and the light source part111 may be constituted by a measuring light source element 116 and acorrecting light source element 117. In this case, when the correctinglight source element 117 is lit and the measuring light source element116 is unlit, the amount of light (light from the correcting lightsource element) 118 received in the light receiving part 112 is theamount of received light for correction (amount of received light in thefirst distance Y1), and when the correcting light source element 117 isunlit and the measuring light source element 116 is lit, the amount oflight (light from the measuring light source element) 119 received inthe light receiving part 112 is the amount of received light formeasurement (amount of received light in the second distance Y2).

EMBODIMENT 8

FIG. 21 is a block diagram of the apparatus of measuring the thicknessof subcutaneous fat using light in Embodiment 8 of the presentinvention. It differs from the apparatus of measuring the thickness ofsubcutaneous fat using light in Embodiment 7 shown in FIG. 17 in that apressure detecting part 124 detecting that the pressure applied to thesurface of the organism 101 by the forming part 110 reaches a levelequal to or greater than a predefined value is connected to the formingpart 110 in place of the pressure measuring part. Other aspects ofconfiguration are same as those of the apparatus of measuring thethickness of subcutaneous fat using light in Embodiment 7, and thereforedescriptions thereof are not presented here.

If the pressure applied to the forming part 110 is increased while theforming part 110 is contacted against the surface of the organism, thethickness of the subcutaneous fat 106 is compressed and its thickness isreduced, but the thickness converges at a certain value. When thepressure at which the thickness of subcutaneous fat converges is definedas the predefined value, by applying a pressure equal to or greater thanthe predefined value to the surface of the organism 101, measurementscan be carried out while the thickness of the subcutaneous fat 106 iskept stable. Also, the subcutaneous fat 106 is compressed and therebyits thickness is reduced, whereby individual differences due tovariations in the amount of blood in the subcutaneous fat 106 arereduced. If the predefined value of contact force is about 2 kg orgreater (about 7 kPa or greater when converted to pressure because theforming part 110 has a disk shape with the diameter of about 60 mm), thethickness of the subcutaneous fat 106 is advantageously stabilized. Inthis embodiment, the predefined value of pressure is about 8.75 kPa.

The procedure of measurement will now be described. As a firstoperation, the forming part 110 is contacted against the surface of theorganism 101 while the light source 111 is unlit.

As a second operation, if the amount of light received in the lightreceiving part 112 is 100 pW or smaller, and a pressure equal to orgreater than 8.75 kPa is detected in the pressure detecting part 124,the light source element 117 is lit up when it is ensured that theentire light receiving part 112 contacts the surface of the organism andthe forming part 110 is contacted against the surface of the organismwith a sufficient pressure, and in this state, a signal for start ofmeasurement is inputted from the communication part 122 or input part123.

As a third operation, the received amount of light 118 propagating fromthe correcting light source element 117 through the inside of theorganism and arriving at the light receiving part 112, namely the amountof received light for correction (amount of received light in the firstdistance Y1) is measured.

Then, as a fourth operation, the received amount of light 119propagating from the measuring light source element 116 through theinside of the organism and arriving at the light receiving part 112,namely the amount of received light for measurement (amount of receivedlight in the second distance Y2) while the correcting light sourceelement 117 is unlit and the measuring light source element 116 is lit.

How the thickness of the subcutaneous fat 106 is calculated in thecalculation part 120 will now be described. The relation between theamount of received light for measurement and the thickness of thesubcutaneous fat 106 is shown in FIG. 22. In FIG. 22, the white circleshows the relation between the amount of received light for measurementand the thickness of the subcutaneous fat 106, and the dotted line isits primary regression line. Thus, by using a relational expression ofthis primary regression line and the measured amount of received lightfor measurement, the thickness of subcutaneous fat can be determined.According to this measurement method, measurements are carried out whilethe thickness of the subcutaneous fat 106 is kept stable, thus making itpossible to measure the thickness of subcutaneous fat with highreproducibility and accuracy.

In addition, the correction of influences of the skin 105 will bedescribed. The relation between a parameter of Y2/Y1 with the amount ofreceived light for measurement (amount of received light in the seconddistance Y2) divided by the amount of received light for correction(amount of received light in the first distance Y1) and the thickness ofthe subcutaneous fat 106 is shown in FIG. 23. In FIG. 23, the whitecircle shows the relation between the Y2/Y1 and the thickness of thesubcutaneous fat 106, and the dotted line is its primary regressionline. Thus, by using a relational expression of this primary regressionline and the calculated parameter Y2/Y1, the thickness of subcutaneousfat can be determined. According to this measurement method, influencesof the skin 105 can be corrected, thus making it possible to measure thethickness of subcutaneous fat with higher reproducibility and accuracy.

EMBODIMENT 9

FIG. 24 is a block diagram of the apparatus of measuring the thicknessof subcutaneous fat using light in Embodiment 9 of the presentinvention, and FIG. 25 is a top view of a forming part 110 of theapparatus of measuring the thickness of subcutaneous fat using light,seen from the side on which the forming part 110 contacts the surface ofthe organism 101. Aspects identical in configuration to those ofEmbodiment 7 or 8 are not described. A protrusion part 125 that is about5 mm wide, 52.5 mm long and 5 mm high is placed at almost the center ofthe forming part 110, and the light source 111 and the light receivingpart 112 are placed in the protrusion part 125.

Furthermore, if the protrusion part 125 and the forming part 110 areshaped so that the corners of the protrusion part 125 are notsharp-pointed as shown in the top view of FIG. 26( a) and the side viewof FIG. 26( b), a situation in which the organism is pained canadvantageously be eliminated. That is, in FIGS. 26( a) and 26(b), ataper is attached so that the corners of the protrusion part 125 are notsharp-pointed. Also, the protrusion part 125 may be formed so that ithas a curved face over the entire forming part 110 as shown in the topview of FIG. 27( a) and the side view of FIG. 27( b).

The face on which the protrusion part 125 of the forming part 110 isprovided is contacted against the surface of the organism 101, wherebythe surface of the organism 101 is locally pushed by the forming part110 and the protrusion part 125 with stability to reduce the amount ofblood in the subcutaneous fat 106 just below the protrusion part 125.Since the area of the pushed surface is small compared to the case whereit is pushed only by the forming part 110, the amount of blood in thesubcutaneous fat 106 just below the protrusion part 125 furtherdecreases, and thus individual differences in variations associated withthe amount of blood are further reduced.

Also, of light received in the receiving part 112, components of lightthat have propagated through areas other than the area just below theprotrusion part 125 in the organism are more significantly attenuatedthan those that have propagated through the area just below theprotrusion part 125 because they have propagated through areas havinglarger amount of blood than the area just below the protrusion part 125.Therefore, the proportion of components of light that have propagatedthrough the subcutaneous fat 106 just below the protrusion part 125 inthe amount of received light to be measured increases, thus making itpossible to measure the thickness of subcutaneous fat more locally.

The procedure of measurement will now be described. As a firstoperation, the forming part 110 is contacted against the surface of theorganism 101 while the light source 111 is unlit.

As a second operation, if the amount of light received in the lightreceiving part 112 is about 100 pW or smaller, and a pressure equal toor greater than about 8.75 kPa is detected in the pressure detectingpart 124, the light source 111 is lit up when it is ensured that theentire light receiving part 112 contacts the surface of the organism andthe forming part 110 is contacted against the surface of the organismwith a sufficient pressure, and in this state, a signal for start ofmeasurement is inputted from the communication part 122 or input part123.

As a third operation, the amount of received light for correction(amount of received light in the first distance Y1) is determined bymeasuring light 118 arriving at the correcting light receiving element114, and the amount of received light for measurement (amount ofreceived light in the second distance Y2) is determined by measuringlight 119 arriving at the measuring light receiving element 113.

How the thickness of the subcutaneous fat 106 is calculated in thecalculation part 120 will now be described. The relation between theamount of received light for measurement and the thickness of thesubcutaneous fat 106 is shown in FIG. 28. In FIG. 28, the white circleshows the relation between the amount of received light for measurementand the thickness of the subcutaneous fat 106, and the dotted line isits primary regression line. Thus, by using a relational expression ofthis primary regression line and the measured amount of received lightfor measurement, the thickness of subcutaneous fat can be determined.According to this measurement method, measurements are carried out whilethe thickness of the subcutaneous fat 106 is kept stable, thus making itpossible to measure the thickness of subcutaneous fat with highreproducibility and accuracy.

In addition, the correction of influences of the skin 105 will bedescribed. The relation between a parameter of Y2/Y1 with the amount ofreceived light for measurement (amount of received light in the seconddistance Y2) divided by the amount of received light for correction(amount of received light in the first distance Y1) and the thickness ofthe subcutaneous fat 106 is shown in FIG. 29. In FIG. 29, the whitecircle shows the relation between the Y2/Y1 and the thickness of thesubcutaneous fat 106, and the dotted line is its primary regressionline. Thus, by using a relational expression of this primary regressionline and the calculated parameter Y2/Y1, the thickness of subcutaneousfat can be determined. According to this measurement method, influencesof the skin 105 can be corrected, thus making it possible to measure thethickness of subcutaneous fat with higher reproducibility and accuracy.

The method of measuring the thickness of subcutaneous fat using light inone embodiment of the present invention comprising:

-   -   a first step of applying a pressure to the surface of an        organism;    -   a second step of detecting that the pressure reaches a        predetermined value;    -   a third step of irradiating the organism with light; and    -   a fourth step of receiving light propagating through the inside        of the organism and outgoing from the surface of the organism,    -   and further comprising a fifth step of calculating the thickness        of subcutaneous fat of the organism based on the amount of light        received in the fourth step at a time when a predetermined        amount of time passes after it is detected that the pressure        reaches the predetermined value.

As the pressure applied to the surface of the organism increases, thethickness of subcutaneous fat decreases, but the thickness converges ata certain value. The pressure at which the thickness of subcutaneous fatconverges is defined as the predefined value, and the thickness ofsubcutaneous fat is stabilized by applying a pressure equal to orgreater than the predefined value to the surface of the organism. Also,just after the pressure is applied, deformation of the subcutaneous fatand the like is in a transient state, since the resistance occurs withwhich the blood in the pressurized site flows through vessels and thelike before it moves to a non-pressurized site. Hence, the thickness ofsubcutaneous fat is calculated from the amount of received light in thefourth step acquired at a time when a predefined amount of time passesafter a pressure equal to or greater than a predefined value is applied,so that the thickness of subcutaneous fat is stabilized, and thereforethe thickness of subcutaneous fat can be measured with highreproducibility and accuracy.

Here, the predefined amount of time in the fifth step is preferablyabout 200 ms or greater.

The method of measuring the thickness of subcutaneous fat using light inone embodiment of the present invention comprising:

-   -   a first step of applying a pressure to the surface of an        organism;    -   a second step of detecting that the pressure reaches a        predetermined value;    -   a third step of irradiating the organism with light; and    -   a fourth step of receiving light propagating through the inside        of the organism and outgoing from the surface of the organism,    -   and further comprising a fifth step of monitoring variations in        the amount of light received in the fourth step 4 when it is        detected that the pressure reaches the predetermined value, and        calculating the thickness of subcutaneous fat of the organism        based on the amount of received light acquired at the time when        the variations in received light are within a predetermined        value.

As the pressure applied to the surface of the organism increases, thethickness of subcutaneous fat decreases, but the thickness converges ata certain value. When the pressure at which the thickness ofsubcutaneous fat converses is defined as the predefined value, thethickness of subcutaneous fat is stabilized by applying a pressure equalto or greater than the predefined value to the surface of the organism.Also, just after the pressure is applied, deformation of thesubcutaneous fat and the like is in a transient state, since theresistance occurs with which the blood in the pressurized site flowsthrough vessels and the like before it moves to a non-pressurized site.Hence, the thickness of subcutaneous fat is calculated from the amountof received light in the fourth step after the amount of received lightis stably within a predefined value, so that the thickness ofsubcutaneous fat is stabilized, and therefore the thickness ofsubcutaneous fat can be measured with high reproducibility and accuracy.

Here, if the variation in the amount of received light is within about±10%, the thickness of subcutaneous fat is advantageously stabilized.

Here, if the predefined value in the second step is about 7 kPa orgreater, the thickness of subcutaneous fat is advantageously stabilized.

Also, if the central wavelength of light applied in the third step is inthe range of from about 500 nm to 1000 nm, there are advantageouslydifferences in absorption and scattering characteristics between tissuesof skin, muscle and fat.

The apparatus of measuring the thickness of subcutaneous fat using lightof one embodiment of the present invention is characterized bycomprising:

-   -   a pressure applying part applying a pressure to the surface of        an organism;    -   a pressure detecting part detecting that the pressure reaches a        predetermined value;    -   a light source part irradiating the organism with light; and    -   a light receiving part receiving the light propagating through        the inside of the organism and outgoing from the surface of the        organism,    -   the apparatus further comprising a calculation part calculating        the thickness of subcutaneous fat of the organism based on the        amount of light received on the light receiving part acquired at        a time when a predetermined amount of time passes after it is        detected that the pressure reaches the predetermined value.

As the pressure applied to the surface of the organism increases, thethickness of subcutaneous fat decreases, but the thickness converges ata certain value. When the pressure at which the thickness ofsubcutaneous fat converges is defined as the predefined value, thethickness of subcutaneous fat is stabilized by applying a pressure equalto or greater than the predefined value to the surface of the organism.Also, just after the pressure is applied, deformation of thesubcutaneous fat and the like is in a transient state, since theresistance occurs with which the blood in the pressurized site flowsthrough vessels and the like before it moves to a non-pressurized site.Hence, the thickness of subcutaneous fat is calculated from the amountof received light in the light receiving part acquired at a time when apredefined amount of time passes after a pressure equal to or greaterthan a predefined value is applied, so that the thickness ofsubcutaneous fat is stabilized, and therefore the thickness ofsubcutaneous fat can be measured with high reproducibility and accuracy.

Also, the apparatus of measuring the thickness of subcutaneous fat usinglight of one embodiment of the present invention comprising:

-   -   a pressure applying part applying a pressure to the surface of        an organism;    -   a pressure detecting part detecting that the pressure reaches a        predetermined value;    -   a light source part irradiating the organism with light; and    -   a light receiving part receiving the light propagating through        the inside of the organism and outgoing from the surface of the        organism,    -   the apparatus further comprising a calculation part monitoring        variations in the amount of light received in the light        receiving part when it is detected that the pressure reaches the        predetermined value, and calculating the thickness of        subcutaneous fat of the organism based on the amount of received        light acquired at a time when the variations in the amount of        received light are within a predetermined value.

As the pressure applied to the surface of the organism increases, thethickness of subcutaneous fat decreases, but the thickness converges ata certain value. When the pressure at which the thickness ofsubcutaneous fat converges is defined as the predefined value, thethickness of subcutaneous fat is stabilized by applying a pressure equalto or greater than the predefined value to the surface of the organism.Also, just after the pressure is applied, deformation of thesubcutaneous fat and the like is in a transient state, since theresistance occurs with which the blood in the pressurized site flowsthrough vessels and the like before it moves to a non-pressurized site.Hence, the thickness of subcutaneous fat is calculated from the amountof received light in the light receiving part acquired after the amountof received light is stably within a predefined value, so that thethickness of subcutaneous fat is stabilized, and therefore the thicknessof subcutaneous fat can be measured with high reproducibility andaccuracy.

Preferably, a generally planar face in contact with the surface of theorganism at the pressurized portion ensures that an even pressure isapplied on the surface of the organism to be measured.

Also, a plurality of light sources are preferably provided in the lightsource part. Also, a plurality of light receiving elements may beprovided in the light receiving part.

Also, if there are a light source and a light receiving element providedso that the distance between the light source and the light receivingelement is a first distance of about 15 mm to 30 mm, and a light sourceand a light receiving element provided so that the distance between thelight source and the light receiving element is a second distance ofabout 35 mm to 80 mm, and the amount of received light in the lightreceiving element with the first distance equals Y1, and the amount ofreceived light in the light receiving element with the second distanceequals Y2, the thickness of subcutaneous fat of the organism iscalculated using the ratio between Y2 and Y1 in the calculation part.From this way, influences of colors of skin can be eliminated, thusmaking it possible to measure the thickness of subcutaneous fat withhigher reproducibility and accuracy.

The method of measuring the thickness of subcutaneous fat of the presentinvention and the apparatus for use in the method will be described indetail below using the drawings.

EMBODIMENT 10

FIG. 30 is a block diagram of the apparatus of measuring the thicknessof subcutaneous fat using light in Embodiment 10 of the presentinvention, and FIG. 31 is a top view of a forming part 210 being apressure applying part of the apparatus of measuring the thickness ofsubcutaneous fat using light seen from the side on which the formingpart 210 contacts the surface of an organism 201.

The forming part 210 forming the surface of the organism 201 into almosta flat shape is provided on the surface of the organism 201 constitutedby three layers of a skin 205, a subcutaneous fat 206 and a muscle 207.The forming part 210 has a disk shape with the diameter of about 60 mm,and is made of black ABS. Furthermore, the material of the forming part210 is not limited as long as it has a low degree of reflection of lightfrom a light source part 211. The forming part 210 has each cornerrounded to prevent a situation in which a sharp-pointed portion abutsagainst the surface of the organism. Furthermore, the forming part 210may have an oval shape or a shape of a flat plate whose corner ischamfered that is about 40 mm long and 60 mm wide.

The light source part 211 and a light receiving part 212 are provided inthe forming part 210. The light receiving part 212 is composed of ameasuring light receiving element 213 (second light receiving element)and a correcting light receiving element 214. (first light receivingelement). The distance between the measuring light receiving element 213and the light source 211 is about 45 mm, and the distance between thecorrecting light receiving element 214 and the light source 211 is about22.5 mm. The emission orifice of light emitted from the light sourcepart 211 has a diameter of about 1.5 mmφ, and the incident orifice oflight of the measuring light receiving element 213 and correcting lightreceiving element 214 has a diameter of about 1.5 mmφ. Furthermore, thedistance between the measuring light receiving element 213 and the lightsource part 211 is preferably in the range of from about 35 mm to 80 mm(second distance), and the distance between the correcting lightreceiving element 214 and the light source 211 (first distance) ispreferably in the range of from about 15 mm to 30 mm. When the lightsource 211 is lit up, an amount of received light for correction (Y1) isreceived in the correcting light receiving element 214, and an amount ofreceived light for measurement (Y2) is received in the measuring lightreceiving element 213.

Here, the light source part is constituted by one light source 211, andthe light receiving part 212 is constituted by the measuring lightreceiving element 213 and the correcting light receiving element 214,but instead thereof, the configuration shown in the block diagram ofFIG. 32 and a forming part 210 a of FIG. 33 may be used. Specifically,as shown in the block diagram of FIG. 32 and the top view of the formingpart 210 a of FIG. 33, a light receiving part 212 a may be constitutedby one light receiving element, and a light source part 211 a may beconstituted by a measuring light source element 216 and a correctinglight source element 217. In this case, the amount of light 218 receivedin the light receiving part 212 a is the amount of received light forcorrection (amount of received light in the first distance Y1) when thecorrecting light receiving element 217 is lit and the measuring lightreceiving element 216 is unlit, and the amount of light 219 received inthe light receiving part 212 is the amount of received light formeasurement (amount of received light in the second distance Y2) whenthe correcting light source element 217 is unlit and the measuring lightsource element 216 is lit.

Here, the light source part 211 uses a laser diode with the centralwavelength about 785 nm as a light source element. Furthermore, it ispreferable the light source element is a light source element such as alaser diode or LED with the central wavelength of about 500 nm to 1000nm. In addition, if a light guide component such as optical fibers isused for guiding light from the light source element to the surface ofthe organism, heat generated in the light source element isadvantageously prevented from being transferred to the surface of theorganism. Furthermore, the same may hold true for the light source part211 a described with FIGS. 32 and 33.

The light receiving part 212 uses a photodiode as a light receivingelement. Furthermore, the light receiving element may be a photoelectricconversion element such as CdS. Also, a light guide component such asoptical fibers may be used for guiding light from the surface of theorganism to the light receiving element. Furthermore, the same may holdtrue for the light receiving part 212 a described with FIGS. 32 and 33.

In FIG. 30, a pressure detecting part 215 detecting that the pressureapplied to the surface of the organism 201 by the forming part 210reaches a predefined value is connected to the forming part 210. If thepressure applied to the forming part 210 is increased while the formingpart 210 is contacted against the surface of the organism, the thicknessof the subcutaneous fat 206 is compressed and its thickness is reducedas the pressure is increased, but the thickness converges at a certainvalue. If the pressure at which the thickness of subcutaneous fatconverses is defined as the predefined value, measurements can becarried out while the thickness of the subcutaneous fat 206 is keptstable by applying a pressure equal to or greater than the predefinedvalue to the surface of the organism 201. Also, the subcutaneous fat 206is compressed and thereby its thickness is reduced, whereby individualdifferences due to variations in the amount of blood in the subcutaneousfat 206 are reduced.

FIG. 34 shows the relation between the contact force and the thicknessof subcutaneous fat when a plate similar in shape to the forming part210 is contacted against three different organisms. From FIG. 34, it canbe said that if a predefined value of contact force is about 2 kg orgreater, the thickness of the subcutaneous fat 206 is advantageouslystabilized. Here, the area of the forming part 210 is about 28.26 cm²,and therefore the predefined value of pressure is about 7 kPa in thisembodiment.

Therefore, as long as a pressure equal to or greater than the predefinedvalue is applied to the surface of the organism 201, the thickness ofthe subcutaneous fat 206 is kept stable even if there are somevariations in pressure. Therefore, the thickness of subcutaneous fat canbe measured simply and accurately only by abutting the forming part 210against the surface of the organism by a human hand with a pressureequal to or greater than a predefined value without using a specialmeasure for abutting the forming part 210 against the surface of theorganism 201.

The calculation part 220 calculates the thickness of the subcutaneousfat 206 based on the amount of received light obtained in the lightreceiving part 212 after a predefined amount of time from a time whenthe pressure equal to or greater than a predefined value is detected inthe pressure detecting part 215. That is, the amount of received lightis not stabilized at the moment that the pressure reaches the predefinedvalue because the blood in organic tissues undergoes resistances inblood vessels and the like, and the blood and the like are on the movewhile the thickness of subcutaneous fat still varies, and therefore thethickness of subcutaneous fat is calculated from the amount of receivedlight acquired after a predefined amount of time during which variationsin thickness of subcutaneous fat are eliminated. Here, the predefinedamount of time is about 200 ms or greater. The thickness of thesubcutaneous fat 206 calculated in the calculation part 220 is displayedon a display part 221, is transmitted through a communication part 222to other apparatuses as data.

Also, by inputting data such as the height, the weight, the age, the sexand the site to be measured directly from an input part 223 or fromother apparatus through the communication part 222, the percent of bodyfat correlative with the thickness of the subcutaneous fat 206 can becalculated in the calculation part 220 and displayed on the display part221, and data can be transferred to other apparatuses by thecommunication part 222.

The procedure of measurement will now be described. As a firstoperation, the forming part 210 is contacted against the surface of theorganism 201 while the light source 211 is unlit.

As a second operation, if the amount of light received in the lightreceiving part 212 is about 100 pW or smaller, and the value measured inthe pressure measuring part 215 is about 7 kg or greater, the lightsource 211 is lit up when it is ensured that the entire light receivingpart 212 contacts the surface of the organism and the forming part 210is contacted against the surface of the organism with a pressure equalto or greater than a predefined value, and in this state, a signal forstart of measurement is inputted from the communication part 222 orinput part 223.

As a third operation, the amount of received light for correction(amount of received light in the first distance Y1) is determined bymeasuring light arriving at the correcting light receiving element 214after about 200 ms, and the amount of received light for measurement(amount of received light in the second distance Y2) is determined bymeasuring light arriving at the measuring light receiving element 213.

Furthermore, the first, second and third operations are carried out inthis order in the procedure described above, but the first, second andthird operations may be carried out in any order. Also, the light source1 is not lit when the first operation is carried out in the proceduredescribed above, but the light source may be lit up before the firstoperation is carried out.

How the thickness of the subcutaneous fat 206 is calculated in thecalculation part 220 will now be described. One example of relationbetween the amount of received light for measurement and the thicknessof the subcutaneous fat 206 is shown in FIG. 35. A plurality of primaryregression lines each showing the correlation between the amount ofreceived light for measurement and the thickness of subcutaneous fat aredetermined in advance, and the primary regression lines and the amountof received light for measurement are used, whereby the thickness ofsubcutaneous fat can be measured with high reproducibility and accuracy,variations in pressure applied to the surface of the organism andvariations in the amount of blood in the organism being alleviated.Here, one example of relation between the amount of received light formeasurement and the thickness of subcutaneous fat when the pressure isnot controlled is shown in FIG. 36. The example of FIG. 36 hassignificant variations and is inferior in correlation to the example ofFIG. 35 in which the pressure is controlled.

However, influences of colors of the skin 205 and the like are includedin the amount of received light for measurement Y2 as error factors. Theamount of received light for correction Y1 is used for correcting theinfluences of colors of the skin 205 and the like.

The relation between a parameter of Y2/Y1 with the amount of receivedlight for measurement (amount of received light in the second distanceY2) divided by the amount of received light for correction (amount ofreceived light in the first distance Y1) and the thickness of thesubcutaneous fat 206 is shown in FIG. 37.

Compared with FIG. 35, variations are apparently alleviated, and it canthus be understood that the amount of received light for correctionbrings about an effect of correlation. Thus, as in the case of usingonly the amount of received light for measurement, the primaryregression line showing the correlation between Y2/Y1 and the thicknessof subcutaneous fat is determined in advance, and the primary regressionline and the Y2/Y1 are used, whereby influences of the skin 205 canfurther be corrected, thus making it possible to measure the thicknessof subcutaneous fat with higher reproducibility and accuracy.

EMBODIMENT 11

The block diagram of the apparatus of measuring the thickness ofsubcutaneous fat using light in Embodiment 11 of the present inventionis similar to those of FIGS. 30 and 31. It differs from the apparatus ofmeasuring the thickness of subcutaneous fat using light of Embodiment 10in that after variations in the amount of received light for measurementand the amount of received light for correction are stably withinpredefined values in the calculation part after the pressure is detectedin the pressure detecting part, the thickness of subcutaneous fat iscalculated from the amount of received light for measurement and theamount of received light for correction. Other aspects of configurationare same as those of the apparatus of measuring the thickness ofsubcutaneous fat using light in Embodiment 10, and therefore thedescription thereof is not presented here.

The procedure of measurement will now be described. As a firstoperation, the forming part 210 is contacted against the surface of theorganism 201 while the light source 211 is unlit.

As a second operation, if the amount of light received in the lightreceiving part 212 is about 100 pW or smaller, and a pressure equal toor greater than about 7 kPa is detected in the pressure detecting part224, the light source element 217 is lit up when it is ensured that theentire light receiving part 212 contacts the surface of the organism andthe forming part 210 is contacted against the surface of the organismwith a sufficient pressure, and in this state, a signal for start ofmeasurement is inputted from the communication part 222 or input part223.

As a third operation, the received amount of light 218 propagating fromthe correcting light source element 217 through the inside of theorganism and arriving at the light receiving part 212, namely the amountof received light for correction (amount of received light in the firstdistance Y1) is measured.

Furthermore, the first, second and third operations are carried out inthis order in the procedure described above, but instead thereof, thefirst, second and third operations may be carried out in any order.Also, the light source 211 is not lit when the first operation iscarried out in the procedure described above, but the light source 211may be lit up before the first operation is carried out.

The calculation part 220 monitors the amount of received light forcorrection, and determines the average of the amount of received lightfor correction when the variation in the amount of received light forcorrection per second reaches to a level within about ±10%.

Then, as a fourth operation, the received amount of light 219propagating from the measuring light source element 216 through theinside of the organism and arriving at the light receiving part 212,namely the amount of received light for measurement (amount of receivedlight in the second distance Y2) while the correcting light sourceelement 217 is unlit and the measuring light source element 216 is lit.The calculation part 220 monitors the amount of received light formeasurement, and determines the average of the amount of received lightfor measurement when the variation in the amount of received light formeasurement per second reaches to a level within about ±10%. Here, thereason why the average of the amount of received light per second isdetermined is that the amount of received light is also influenced bythe pulsating flow of blood flowing through the inside of the organism,and the average over one second or longer is calculated in considerationof the fact that the pulse rate of human being is at one or more persecond, whereby data with no influences of the pulse flow can beobtained.

How the thickness of the subcutaneous fat 206 is calculated in thecalculation part 220 will now be described. The relation between theamount of received light for measurement and the thickness of thesubcutaneous fat is shown in FIG. 35. In FIG. 35, the white circle showsthe relation between the amount of received light for measurement andthe measured thickness of the subcutaneous fat 206, and the solid lineis its primary regression line. Thus, by using a relational expressionof this primary regression line and the average of the measured amountof received light for measurement, the thickness of subcutaneous fat canbe determined. According to this measurement method, measurements arecarried out while the thickness of the subcutaneous fat 206 is keptstable, thus making it possible to measure the thickness of subcutaneousfat with high reproducibility and accuracy.

In addition, the correction of influences of colors of the skin 205 andthe like will be described. The relation between a parameter of Y2/Y1with the average of the amount of received light for measurement (amountof received light in the second distance Y2) divided by the average ofthe amount of received light for correction (amount of received light inthe first distance Y1) and the thickness of the subcutaneous fat 206 isshown in FIG. 37. In FIG. 37, the white circle shows the relationbetween the Y2/Y1 and the thickness of the subcutaneous fat 206, and thesolid line is its primary regression line. Thus, by using a relationalexpression of this primary regression line and the calculated parameterY2/Y1, the thickness of subcutaneous fat can be determined. According tothis measurement method, influences of colors of the skin 205 and thelike can be corrected, thus making it possible to measure the thicknessof subcutaneous fat with higher reproducibility and accuracy.

As apparent from the above, according to the present invention, it ispossible to provide a compact method of measuring biological informationusing light and apparatus of measuring biological information usinglight that can measure biological information such as the thickness ofsubcutaneous fat, the percent of body fat, the concentration of glucosein an organism and the concentration of oxygen in an organism can bemeasured with high reproducibility and accuracy.

As apparent from the above, according to the present invention, there isprovided a method of measuring the thickness of subcutaneous fat usinglight and an apparatus of measuring the thickness of subcutaneous fatusing light capable of measuring biological information such as thethickness of subcutaneous fat, the percent of body fat, theconcentration of glucose in an organism and the concentration of oxygenin an organism with high reproducibility and accuracy.

1. A method of measuring biological information utilizing an apparatusof measuring said biological information using light comprising: a lightsource part adapted to irradiate an organism; a light receiving partreceiving light propagating from said light source part through aninside of said organism and outgoing from a surface of said organism; aforming part adapted to form said surface of said organism into apredetermined shape by applying a pressure thereto; a protrusion partbeing provided on a face of said forming part contacting said surface ofsaid organism; a pressure detecting part detecting said pressure appliedto said surface of said organism by said forming part, said pressuredetecting part is connected to said forming part; and a calculation partcalculating said biological information of said organism usinginformation of a relation between an amount of said received light andsaid biological information of said organism previously determined,based on said amount of said light received in said light receivingpart, at least one of said light source part and said light receivingpart is provided on said protrusion part, said calculation partcalculates said biological information of said organism based on saidamount of said received light when it is detected that said pressurereaches said level equal to or greater than said predefined value, saidmethod comprising: a first step of utilizing said forming part to formsaid surface of said organism into said predetermined shape by applyingsaid pressure thereto; a second step of utilizing said light source partto irradiate said organism with said light; a third step of utilizingsaid light receiving part to receive said light propagating through saidinside of said organism and outgoing from said surface of said organism;and a fourth step of utilizing said calculation part to calculate saidbiological information of said organism using said information of saidrelation between said amount of said received light and said biologicalinformation of said organism previously determined, based on said amountof said light received in said third step, wherein in said fourth step,said biological information of said organism is calculated using saidinformation of said relation between said amount of said received light,which has been acquired after said pressure reaches a level equal to orgreater than a predefined value, and said biological information of saidorganism previously determined, based on said amount of said receivedlight acquired after said pressure reaches said level equal to orgreater than said predefined value.
 2. The method of measuringbiological information according to claim 1, wherein said predefinedvalue of said pressure is about 7 kPa or greater.
 3. A method ofmeasuring biological information utilizing an apparatus of measuringsaid biological information using light comprising: a light source partadapted to irradiate an organism; a light receiving part receiving lightpropagating from said light source part through an inside of saidorganism and outgoing from a surface of said organism; a forming partadapted to form said surface of said organism into a predetermined shapeby applying a pressure thereto; a protrusion part being provided on aface of said forming part contacting said surface of said organism; apressure measuring part measuring said pressure applied to said surfaceof said organism by said forming part, said pressure measuring part isconnected to said forming part; and a calculation part calculating saidbiological information of said organism using information of a relationat least between an amount of said received light and said biologicalinformation of said organism previously determined, based on said amountof said light received in said receiving part and said pressure measuredin said pressure measuring part, at least one of said light source partand said light receiving part is provided on said protrusion part, saidmethod comprising: a first step of utilizing said forming part to formsaid surface of said organism into said predetermined shape by applyingsaid pressure thereto; a second step of utilizing said light source partto irradiate said organism with said light; a third step of utilizingsaid light receiving part to receive said light propagating through saidinside of said organism and outgoing from said surface of said organism;a fourth step of utilizing said calculation part to calculate saidbiological information of said organism using said information of saidrelation at least between said amount of said received light and saidbiological information of said organism previously determined, based onsaid amount of said light received in said third step; and a fifth stepof utilizing said pressure measuring part to measure said pressure,wherein in said fourth step, said biological information of saidorganism is calculated using said information of said relation betweensaid amount of said received light, said pressure and said biologicalinformation of said organism previously determined, based on said amountof said light received in said third step and said pressure measured insaid fifth step.
 4. The method of measuring biological informationaccording to claim 1 or 3, wherein a central wavelength of said lightapplied in said second step is a wavelength of about 500 nm to 1000 nm.5. The method of measuring biological information according to claim 1or 3, wherein in said fourth step, said biological information of saidorganism is calculated at a time when a predetermined amount of timepasses after said pressure reaches a predefined value.
 6. The method ofmeasuring biological information according to claim 5, comprising afurther step of detecting that said pressure reaches said predefinedvalue, wherein in said fourth step, said biological information of saidorganism is calculated based on said amount of said light received insaid third step at a time when a predetermined amount of time passesafter it is detected that said pressure reaches said predefined value.7. The method of measuring biological information according to claim 6,wherein said predetermined amount of time is about 200 ms or greater. 8.The method of measuring biological information according to claim 1 or3, wherein in said fourth step, said biological information of saidorganism is calculated after said amount of said received light isstabilized.
 9. The method of measuring biological information accordingto claim 8, comprising a further step of detecting that said pressurereaches said predefined value, wherein in said fourth step, variationsin said amount of said light received in said third step are monitoredwhen it is detected that said pressure reaches said predefined value,and said biological information of said organism is calculated based onsaid amount of said received light acquired when said variations in saidamount of received light are within a predetermined value.
 10. Themethod of measuring biological information according to claim 9, whereinsaid variations in said amount of received light being within about±10%.
 11. An apparatus of measuring biological information using lightcomprising: a light source part adapted to irradiate an organism; alight receiving part receiving light propagating from said light sourcepart through an inside of said organism and outgoing from a surface ofsaid organism; a forming part adapted to form said surface of saidorganism into a predetermined shape by applying a pressure thereto; aprotrusion part being provided on a face of said forming part contactingsaid surface of said organism; a pressure detecting part detecting saidpressure applied to said surface of said organism by said forming part,said pressure detecting part is connected to said forming part; and acalculation part calculating said biological information of saidorganism using information of a relation between an amount of saidreceived light and previously determined biological information of saidorganism, based on said amount of said light received in said lightreceiving part, wherein at least one of said light source part and saidlight receiving part is provided on said protrusion part, and saidcalculation part calculates said biological information of said organismbased on said amount of said received light when it is detected thatsaid pressure reaches a level equal to or greater than a predefinedvalue.
 12. An apparatus of measuring biological information using lightcomprising; a light source part adapted to irradiate an organism; alight receiving part receiving light propagating from said light sourcepart through an inside of said organism and outgoing from a surface ofsaid organism; a forming part adapted to form said surface of saidorganism into a predetermined shape by applying a pressure thereto; aprotrusion part being provided on a face of said forming part contactingsaid surface of said organism; a pressure measuring part measuring saidpressure applied to said surface of said organism by said forming part,said pressure measuring part is connected to said forming part; and acalculation part calculating said biological information of saidorganism using information of a relation between an amount of saidreceived light, said pressure and previously determined biologicalinformation of said organism, based on said amount of said lightreceived in said receiving part and said pressure measured in saidpressure measuring part, wherein at least one of said light source partand said light receiving part is provided on said protrusion part. 13.The apparatus of measuring biological information using light accordingto claim 11 or 12, wherein said face of said forming part contactingsaid surface of said organism is substantially flat.
 14. The apparatusof measuring biological information using light according to claim 11 or12, wherein said light source part and said light receiving part areprovided on said protrusion part.
 15. The apparatus of measuringbiological information using light according to claim 11 or 12, whereinsaid light source part has a plurality of light sources.
 16. Theapparatus of measuring biological information using light according toclaim 15, wherein said light source part has said light sources providedso that a distance between a first of said light sources and said lightreceiving part is a first distance of about 15 mm to 30 mm and adistance between a second of said light sources and said light receivingpart is a second distance of about 35 mm to 80 mm, and if said amount oflight received in said light receiving part from said light source withsaid first distance equals Y1, and said amount of light received in saidlight receiving part from said light source with said second distanceequals Y2, said calculation part calculates said biological informationof said organism using a ratio between said Y2 and said Y1.
 17. Theapparatus of measuring biological information using light according toclaim 11 or 12, wherein said light receiving part has a plurality oflight receiving elements.
 18. The apparatus of measuring biologicalinformation using light according to claim 17, wherein said lightreceiving part has said light receiving elements provided so that adistance between said light source part and a first of said lightreceiving elements is a first distance of about 15 mm to 30 mm and adistance between said light source part and a second of said lightreceiving elements is a second distance of about 35 mm to 80 mm, and ifsaid amount of light received in said light receiving element with saidfirst distance equals Y1, and said amount of light received in saidlight receiving element with said second distance equals Y2, saidcalculation part calculates said biological information of said organismusing a ratio between said Y2 and said Y1.
 19. The apparatus ofmeasuring biological information using light according to claim 11 or12, comprising: a display part displaying said biological information ofsaid organism calculated in said calculation part; a communication partcommunicating said biological information of said organism to and fromexternal apparatuses; and an input part for inputting measurementconditions of said organism.